A method and a device for controlling an internal combustion engine having an exhaust gas aftertreatment system are described in German Published Patent Application No. 199 06 287. In the system described therein, a particle filter may be used which may filter out particles contained in the exhaust gas. In order to accurately control an internal combustion engine having an exhaust gas aftertreatment system, the state of the exhaust gas aftertreatment system may be required to be known. In particular, the loading state of the filter, i.e., the quantity of filtered particles, may be required to be known.